College Basketball is set to dominate the sports world for the next three weeks now that the field for the 2018 NCAA Tournament has officially been set. Sixty-eight teams will compete during March Madness in hopes of winning the national championship.

The action begins Tuesday with the “First Four” matchups that will trim the field down to 64 teams. The March Madness schedule will include 12 days of basketball taking place in 14 different cities. It’ll take four straight wins—five wins for teams in the First Four—to reach the Final Four and six consecutive victories to win the national championship in the one-and-done tournament.

Most of the first-round matchups are set, and the rest will be known by Wednesday night. The bracket will determine each winner’s upcoming opponent.

Virginia, Villanova, Kansas and Xavier are the No.1 seeds that sit atop the four regions. The defending national champion North Carolina Tar Heels are the No.2 seed in the West region. Gonzaga was defeated in last year’s national title game, and they are the No.4 seed in that same region.

Half of the teams that reached the 2017 Final Four didn’t even make it into the field for the 2018 NCAA Tournament. It’s been 11 years since the national champions successfully defended their title, though North Carolina has reached the championship game in two straight years.

Kyle Guy #5 of the Virginia Cavaliers celebrates with teammates after being named tournament MVP after defeating the North Carolina Tar Heels 71-63 during the championship game of the 2018 ACC Men's Basketball Tournament at Barclays Center on March 10, 2018 in the Brooklyn borough of New York City. The Cavaliers are the No.1 overall seed in March Madness 2018. Photo: Abbie Parr/Getty Images

Let’s take a look at dates and sites for each round of March Madness 2018.